| Abstract: | The glass transition temperature of systems based on epoxy resin and a number of diamines has been determined by using a torsion pendulum. An equation relating composition and crosslink density with the glass transition temperature has been established which gives reasonable predictions of the glass transition temperatures for systems based on aliphatic or aromatic amines and methylated amines and for systems containing a monofunctional epoxy diluent. The equation may be used to predict Tg for systems with non-stoichiometric quantities of curing agent and blends of amines. Deviation of the predicted and observed values for Tg is interpreted in terms of differences between definitions of Tg used by other workers and, also the occurrence of competing side reactions during polymerization which lead to additional crosslinks. |
